Centrifugally rolling granulating device and method of treating powder and granular material using the device

ABSTRACT

A centrifugal tumbling granulating apparatus  1  comprises a fixed wall  7  having a grain contact portion  7   a  which is in contact with powder grains  2  and of which a horizontal section is formed in a circular shape, and a rotating disk  5  provided a clearance  12  away from an inner side of the fixed wall  7  and rotating in a horizontal direction by a motor  13 , wherein an air supply device  21  for supplying drying air  22  to an upper surface side of the rotating disk  5  is provided above the rotating disk  5 . The air supply device  21  has a cylindrical straight tube portion  25 , and an air supply port  23  formed in a cone shape, and is disposed in a centrifugal tumbling chamber  6  to be movable in an up-and-down direction. During a granulating step, the air supply device  21  stops to supply the dry air  22  and waits at an upper position H. After the granulation processing, the air supply device is lowered at a lower position L and supplies the dry air  22  onto the rotating disk  5  to dry granulated substances. As a result, the granulating apparatus capable of efficiently obtaining, in a single apparatus, spherical particles of which each particle size is small and which exist within a narrow range of particle size distribution and of which deviation from spherical form is small is provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is entitled to the benefit of and incorporates byreference essential subject matter disclosed in PCT Application No.JP00/03645 filed on Jun. 5, 2000, and the following Japanese PatentApplications: No. 11-159429 filed on Jun. 7, 1999; No. 11-296762 filedon Oct. 19, 1999; No. 2000-155278 filed on May 25, 2000, all in the nameof Freund Industrial Co., Ltd.

TECHNICAL FIELD

The present invention relates to a granulation processing technology ofpowder grains, and more particularly to a technology effective in thecase of granulating spherical particles of medical supplies, foodstuffsand the like by a centrifugal tumbling granulating apparatus.

BACKGROUND ART

Conventionally, there have been many types of power grain granulatingapparatuses, and granulation processing is performed by various methodssuch as a tumbling granulating method, an agitating granulating method,an extruding granulating method, a disintegration granulating method, afluidized bed method or the like by using these apparatuses. Among thesemethods, the most optimum method of obtaining spherical or nearlyspherical grains is the tumbling granulating method that granulates thepowder during tumble. A tumbling granulating apparatus for performingthis is roughly classified into the following two types. That is, thereare a type of rotating a container body f formed in a drum shape, anoblique shape, an oblique cone shape or the like, and a type ofdisposing a rotating disk on a bottom portion of a cylindrical containerand of tumbling powder grains thereon, for example, similarly to anapparatus that has been disclosed in Japanese Patent Publication No.46-10878 or Japanese Patent Publication No. 46-22544.

The apparatus that is the type of rotating the container is mainly usedin granulation of ores, fertilizers or the like, and generatesrelatively large particles existing within a wide range of a particlesize distribution. On the other hand, the apparatus that is the type ofrotating the disk is also called a centrifugal tumbling granulatingapparatus (hereinafter denoted briefly by a CF apparatus), and givesparticles centrifugal force caused by rotation of the rotating disk andthereby performs spherical granulation. Therefore, the apparatus of thistype can obtain small granulated substances existing within a narrowrange of the particle size distribution, and so is generally used infields of medical supplies, foodstuffs or the like.

In the CF apparatus combining the cylindrical container and the rotatingdisk with each other, a narrow annular slit is formed between an innerwall of the cylindrical container and an outer edge portion of therotating disk. The above-mentioned slit has a narrow width in order toprevent particles in the container from falling from the rotating disk,and can supply air thereto in a down to up directions. Further, in theCF apparatus, since the rotating disk is rotated during supply of airinto this slit, the particles on the rotating disk is tumbled by usingthe centrifugal force and thereby performs the spherical granulation.

However, in the CF apparatus like this, since the slit formed around therotating disk has a narrow width, flow amount of air (slit air) passingthrough the slit is small and so hardly contributes to drying ofparticles generated. Accordingly, the CF apparatus itself is poor in acapacity of drying, and the generated spherical particles aretransferred to another drying device and thereby are dryly processed.That is, the generated particles are taken out of the CF apparatus, andare dried in another fluidized bed device or the like, and are formedinto products. Therefore, the good spherical particles have beenobtained, but there arises a problem of productivity. So, improvementthereof is desired.

Thereupon, as disclosed in Japanese Patent Publication No. 61-8736,Japanese Patent Laid-Open No. 62-65729, Japanese Patent Laid-Open No.59-49838 or the like, a tumbling granulating apparatus combining acylindrical container and a rotating disk with each other has beendeveloped by adding a drying function thereto, and has recently beensold at markets as a multifunction type granulating coating apparatus.For example, a Spir-A-Flow (a trade name) or the like made at FreundIndustrial Co, Ltd. is an example thereof. In the apparatus of thisSpir-A-Flow, a ventilation portion is provided in a rotating disk, andair is introduced from a down direction of this ventilation portion,such that granulation and drying processings can be performed inside thesame apparatus. That is, such the multifunction type apparatus cansupply air from the above-mentioned ventilation portion along with orafter the granulation processing, and thereby make the granulatedsubstances drying. Therefore, since it is not necessary to transfer thegenerated substances to another drying device and to dry the generatedsubstances, enhancement in the productivity thereof can be achieved.

On the other hand, besides the device in which the ventilation portionlike this is formed, for example, a device, as disclosed in JapanesePatent Laid-Open No. 61-242628, has also been proposed such that a slitformed between a cylindrical container and a rotating disk has a widewidth to increase flow amount of slit air. In this device, since powdersare easy to fall from the slit in accordance with enlargement of theslit width, a slit portion is further provided with a powder fallprevention mechanism. In this apparatus, while the powders are preventedfrom falling from the slit portion by this mechanism, enhancement of thedrying capacity is achieved by the slit air amount increased. Some ofthe multifunction type apparatuses described above are designed toimprove the drying capacity by the slit air amount increased, too.

In these apparatuses, a fluidized layer can also be formed in thecontainer by the increased amount of air or slit air supplied from theventilation portion, so that it is possible to granulate particles ofvarious shapes from heavy spherical particles to light amorphousparticles. Moreover, the above-mentioned apparatuses can be used even incoating of particles, and so has widely used as multifunction typeapparatuses capable of performing various granulating coatingprocessings.

However, in manufacture of spherical particles which have smalldeviation from spherical form and exist within a narrow range of theparticle size distribution, researches of inventors have discovered thatproperties of granulated substances obtained by these multifunction typeapparatuses are inferior to properties of granulated substances obtainedby the CF apparatus having no drying function. Recently, in particular,spherical particles that each have a small size and exist within anarrow range of the particle size distribution have been demanded inpharmaceutical manufacture. However, since such granulated substancescan not be manufactured by the above-mentioned multifunction typeapparatuses, improvement thereof has been required.

In the multifunction type apparatuses described above, since powdergrains are subject to buoyancy by air passing through the ventilationportion or the like and is not affected by sufficient tumbling actionand compressing action, the inventors have surmised that properties ofgranulated substances are not improved. To avoid this, however, if thecirculating air amount is decreased, then powder grains can not beprevented from falling from the ventilation portion or the like anddrying capacity thereof is degenerated. Therefore, it is necessary tosecure the air circulating amount equal to or more than a certainvolume, and properties of granulated substances can not avoid loweringin comparison with those manufactured by the CF apparatuses having nodrying function.

Further, in the conventional CF apparatus, properties of granulatedsubjects obtained are good, but a drying function is provided therein,and so it takes time and labor to transfer the granulated subjects toanother drying device as described above, and a problem of productivitythereof has not been solved.

In FIG. 5 disclosed in Japanese Patent Publication No. 46-10878 or FIG.2 and FIG. 3 disclosed in Japanese Patent Publication No. 46-22544, anapparatus has been proposed in which an air suction port is provided inan upper space of a centrifugal tumbling granulating apparatus. However,even if the air suction port is provided at a position remote from therotating disk in this apparatus, then the air suction port has hardlycontributed to drying of granulated substances, and so this apparatushas not practically been utilized.

On the other hand, in the conventional centrifugal tumbling granulatingapparatuses, the above-mentioned cylindrical container is usually formedof materials having no adiabatic characteristic such as stainless steelplate or the like, and therefore the centrifugal tumbling chamber formedabove the rotating disk is directly cooled by the outside air. In orderto perform a granulation processing, a coating processing and the like,substances to be processed in the container are sprayed with an aqueoussolution. However, due to this, the inside of the above-mentionedcontainer comes to a damp atmosphere, and there occur portions having atemperature of the dew point or less in the inner surface of thecentrifugal tumbling chamber. And, moisture existing in the centrifugaltumbling chamber becomes dewing on these portions.

Once such dewing occurs, binder splash or powder adheres to the moistureand is dissolved therein. This results in a function as adhesive, and sothe powder grains adhere thereto. And, since each of the powder grainsacts as a kernel, other powder grains further adhere to the powdergrains and spread over the entire inside surface of the fixed wall.Because of this, it takes time and labor to clean the apparatuses andfurther there arises a problem of giving bad influence on the productyield and operation efficiency of the apparatuses.

Moreover, in the centrifugal tumbling granulating apparatuses, if powdergrains are easy to slip on the surface of the rotating disk, then thisimpedes tumbling motion thereof, and the powder grains are centrifugallytumbled and granulated or are powder-coated certainly, and rotationspeed of the rotating disk can not be raised. As a result, there alsoarises a problem of efficiency in production. Further, since tightgranules, small-quantity processing or the like is difficult to perform,improvement of production capacity has been desired.

Further, in the case of sending air onto the rotating disk from avertical direction, air is sent linearly. Therefore, it is easy to sendair through an upper portion of the rotating disk, and time required topass through the rotating disk is likely to shorten. As a result, therehave also arisen such problems that tumbling of the powder grains is notsatisfactorily promoted and efficiency in processing thereof is notgood. Further, since contact time between an air stream and therespective powder grains is apt to shorten, there have also arisen suchproblems that stay time staying in powder grain layers of the air streambecomes short, and the drying efficiency is difficult to enhance.

An object of the present invention is to provide a granulating apparatuscapable of efficiently manufacturing spherical particles which each havea small particle size and exist within a narrow range of particle sizedistribution and have small deviation from spherical form, in a singleapparatus.

Further, an object of the present invention is to prevent a centrifugaltumbling granulating apparatus having an air supply means above arotating disk, from generating dewing in a centrifugal tumbling chamber.Further, another object of the present invention is to prevent powdergrains on the rotating disk from slipping and to centrifugally tumbleand granulate the powder grains certainly. In addition, another objectof the present invention is to lengthen contact time between an airstream and respective powder grains and thereby to enhance dryingefficiency thereof.

These and other objects and novel features of the present invention willbe apparent from description of the present specification and theaccompanying drawings.

DISCLOSURE OF THE INVENTION

A centrifugal tumbling granulating apparatus that is the presentinvention is characterized by a fixed wall having a grain contactportion which is in contact with powder grains and of which a horizontalsection is formed at least in a circular shape; a rotating disk provideda predetermined clearance away from an inner side of said fixed wall androtating in a horizontal direction by a rotary driving means; and an airsupply means disposed above said rotating disk and close to saidrotating disk, and supplying gas to an upper surface side of saidrotating disk.

Due to this, the centrifugal tumbling granulating apparatus that is thepresent invention can, similarly to the conventional centrifugaltumbling granulating apparatus, granulate heavy spherical particles ofwhich each particle size is small and which exist within a narrow rangeof particle size distribution, and further perform, in the sameapparatus, granulation processing of generated substances after thegranulation processing. Therefore, it is unnecessary to transfer thegenerated substances to other drying devices and then to perform dryingprocessing, and so improvement of the productivity can be achieved.

In this case, said air supply means may supply gas to said rotating diskfrom above the central part of said rotating disk. And, said air supplymeans may have a cylindrical straight tube portion, and an air supplyport which communicates with said straight tube portion and is disposedbelow said straight tube portion and of which a lower end side isenlarged in a radius direction of said portion and is formed like acone. Further, said air supply means may supply gas to said rotatingdisk from above a peripheral part of said rotating disk. In addition,said air supply means may be provided to be movable in an up-and-downdirection between a lower position close to said rotating disk and anupper position more remote from said rotating disk than said lowerposition.

In addition, said air supply means may be disposed in such a state thata part thereof enters into a particle layer of said powder grains. Dueto this, since gas is introduced into particle layers and the granulatedsubstances come to a fluidized state, drying thereof is performed moreefficiently.

Then, said rotating disk may have such a vertical section that aperipheral part thereof faces a center thereof and is inclined downward,and may have a projecting portion in a central part thereof. Further,gas may be supplied to said clearance formed between said fixed wall andsaid rotating disk, from a lower direction thereof to an upperdirection. This gas may be ordinary air, but may use air properlyperformed by dehumidifying, heating or the like.

In addition, said fixed wall may have a dewing prevention means forpreventing an inner surface of said fixed wall from being dewed. Due tothis, first, similarly to the above-mentioned case, dry air can besupplied from above the rotating disk through the air supply means, andthe granulated substances is dried in the same apparatus by this dryair. Therefore, it is unnecessary to transfer the granulated substancesto other drying devices and then to perform drying processing, andthereby improvement of the productivity thereof can be achieved.

And, secondly, said dewing prevention means can prevent an inner surfaceof the rotating disk from being dewed, and adhesion of the powder grainsto the inner surface of the fixed wall is suppressed, and cleaning jobsare alleviated, and at the same time the product yield and apparatusoperation efficiency are improved, and so improvement of the productionefficiency or the like can be achieved.

In this case, said dewing prevention means may comprise an outer wallsurrounding said fixed wall, and an adiabatic space formed between saidfixed wall and said outer wall. As a result, conduction of heat is cutoff in the adiabatic space, and the fixed wall is not affected by theoutside air temperature, and the fixed wall can prevent the innersurface thereof from being dewed even if the fixed wall is cooled by theair.

And, said dewing prevention means may further comprise a pump device forsucking air from the inside of said adiabatic space. In addition, saidadiabatic space may be filled with gas having lower pressure thanatmospheric pressure. At this time, it is preferable that the gas insaid adiabatic space has a pressure of 1.33 Pa or less. Due to this,since the outer circumference of the fixed wall may be surrounded withan adiabatic space which is in a vacuum state, a cutoff action of heatconduction is further strengthened and improvement of the dewingprevention effect can be achieved.

In addition, the powder contact portion of said rotating disk may beformed to have a smooth surface. And, a slip prevention means forpreventing the powder grains on said powder contact portion fromslipping may be provided in the powder contact portion of said rotatingdisk. Due to this, the powder grains are prevented from slipping on therotating disk, and at the same time centrifugal gripping force isstrengthened, and tumbling of the powder grains are activated.Therefore, the powder grains can be centrifugally tumbled and granulatedcertainly, and high speed rotation of the rotating disk, tight granules,improvement of processing capacity of small quantity, and the like maybe achieved.

The rotating disk that should provide a slip prevention means of thepresent invention may be a flat plate or a inclined plate as shown inFIG. 21.

And, in this case, said slip prevention means may be a strip-like grooveradially formed in the powder contact portion of said rotating disk, andsaid strip-like groove may be formed such that a side wall of a frontside along a rotating direction of said rotating disk is smoother thanthat of a rear side along said rotating direction.

In addition, said air supply means may be provided with a swirl flowgenerating means for supplying swirl wind onto said rotating disk. Dueto this, since a swirl movement can be given to the powder grainslocated on the rotating disk, the powder grains are wound up in a spiralrotation shape so as to twist a rope. Therefore, tumbling of the powdergrains can be promoted, and improvement of processing efficiency can beachieved. Further, the air stream is prevented from blowing throughstraightly, and contact time between the air stream and the respectivepowder grains can be lengthened, and so stay time of the air streamstaying in powder grain layer is lengthened, and drying efficiency canbe enhanced.

And, said swirl flow generating means may be a wind introducing platearranged in said air supply means. In addition, said air supply meansmay be disposed in such a state as to incline toward a rotatingdirection of said rotating disk from above said rotating disk, andsupplies a swirl air stream onto said rotating disk. As a result,similarly to the above-mentioned case, the swirl air stream promotes thestumbling of powder grains, and can lengthen the contact time betweenthe air stream and the respective powder grains.

On the other hand, a powder grain processing method that is the presentinvention and that uses a centrifugal tumbling and granulating apparatusdescribed above is characterized by the steps of: charging the powdergrains into said centrifugal tumbling and granulating apparatus;rotating said rotating disk while gas is supplied to an upper directionof said. clearance from a lower direction thereof; and supplying atleast one of solvent, solution, dispersion solution, and. dissolvedsolution, and then performing one of granulation and coating of saidpowder grains.

In this case, gas may be supplied from said air supply means to drygranulated substances of said powder grains, and a swirl air stream maybe supplied from said air supply means. Moreover, powders may be furthersupplied into said centrifugal tumbling and granulating apparatus.

In addition, said air supply means may be movably disposed between alower position close to said rotating disk and an upper position remoterthan said lower position from said rotating disk, and a drying step isperformed, with said air supply means being disposed at said lowerposition.

Further, the granulating step or the coating step may be performed, withsaid air supply means being disposed at said upper position, and thegranulating step or the coating step may be performed, with said airsupply means being disposed at said lower position close to saidrotating disk.

In the above-mentioned granulating step or coating step, granulationprocessing or the coating processing may be performed while gas issupplied from said air supply means, or these processing may beperformed after gas stops to be supplied. The gas to be supplied mayhave a normal temperature or be heated.

In said drying step, it is preferred to perform drying processing whilegas is supplied from said air supply means, and it is further desiredthat gas is heated. However, in the case of supplying dissolvedsubstances and performing the granulation processing and the coatingprocessing and the like, there is also the case of not heating suppliedgas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing a constitution of a centrifugaltumbling granulating coating apparatus that is a first embodiment of thepresent invention.

FIG. 2 is an explanatory view showing a disposing state of an air supplydevice applied to the granulating coating apparatus in FIG. 1.

FIG. 3 is an explanatory view showing a constitution in which clearancebetween a fixed wall and a rotating disk is variably formed in thegranulating coating apparatus of FIG. 1.

FIG. 4 shows a first modified example of the granulating coatingapparatus that is a first embodiment.

FIG. 5 shows a second modified example of the granulating coatingapparatus in a first embodiment.

FIG. 6 shows a third modified example of the granulating coatingapparatus in a third embodiment.

FIG. 7 shows a fourth modified example of the granulating coatingapparatus in a first embodiment.

FIG. 8 shows a fifth modified example of the granulating coatingapparatus in a first embodiment.

FIG. 9 shows a sixth modified example of the granulating coatingapparatus in a first embodiment.

FIG. 10 shows a seventh modified example of the granulating coatingapparatus in a first embodiment.

FIG. 11A is an explanatory view showing a constitution of a principalpart of a centrifugal tumbling granulating coating apparatus that is asecond embodiment of the present invention, and is a cross-sectionalview.

FIG. 11B is an explanatory view showing a constitution of a principalpart of a centrifugal tumbling granulating coating apparatus that is asecond embodiment of the present invention, and is a perspective viewseen from above.

FIG. 12 shows a first modified example of the granulating coatingapparatus in a second embodiment.

FIG. 13A shows a second modified example of the granulating coatingapparatus in a second embodiment.

FIG. 13B shows a second modified example of the granulating coatingapparatus in a second embodiment.

FIG. 14 is an explanatory view showing a constitution of a principalpart of a centrifugal tumbling granulating coating apparatus that is athird embodiment of the present invention.

FIG. 15 is a cross-sectional view showing a constitution of a principalpart of a centrifugal tumbling granulating coating apparatus that is afourth embodiment of the present invention.

FIG. 16 is an explanatory view showing a fragment of a part of the CFapparatus in FIG. 15.

FIG. 17 is an explanatory view showing a disposing state of an airsupply device in the CF apparatus of FIG. 15, and shows a view of theair supply device seen from above after a ceiling portion of acentrifugal tumbling chamber is omitted.

FIG. 18 is an explanatory view of a modified example of an air supplydevice.

FIG. 19A is an explanatory view of a modified example of an air supplydevice, and is a cross-sectional view.

FIG. 19B is an explanatory view of a modified example of an air supplydevice, and is a view of the air supply device seen from above after aceiling portion of a centrifugal tumbling chamber is omitted.

FIG. 20 is an explanatory view showing a constitution of a rotating diskthat is a fifth embodiment of the present invention and which is seenfrom above.

FIG. 21 is a perspective view of the rotating disk in FIG. 20.

FIG. 22A is an explanatory view of a slip prevention groove, and is usedfor a left-hand rotation.

FIG. 22B is an explanatory view of a slip prevention groove, and is usedfor a right-hand rotation.

FIG. 23A is a cross-sectional view of a slip prevention groove, and isused for a left-hand rotation.

FIG. 23B is a cross-sectional view of a slip prevention groove, and isused for a right-hand rotation.

FIG. 24 is an explanatory view showing a constitution of a CF apparatusthat is a sixth embodiment of the present invention.

FIG. 25 is an explanatory view showing an air-sending state of air sentfrom an air supply device.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to the drawings, embodiments of the present inventionwill be described in detail below.

First Embodiment

FIG. 1 is a cross-sectional view showing a constitution of a centrifugaltumbling granulating coating apparatus that is a first embodiment of thepresent invention.

As shown in FIG. 1, a centrifugal tumbling granulating coating apparatus(called a CF apparatus hereinafter) 1 according to the presentembodiment is one for centrifugally tumbling and granulating powdergrains 2 and for forming a coating layer. This CF apparatus 1 performsprocessings of adding binding liquid or powder to the powder grains 2 ata predetermined speed, and of granulating spherical granules or the likeby using each of the powder grains as a kernel or by bonding the powdergrains with one another. Further, this CF apparatus 1 can also formcoating layers on grains or the like by adding powder or binding liquidto the spherical granules or the like during the centrifugal tumblingthereof.

This CF apparatus 1 is composed of a centrifugal tumbling unit 3positioned in the upper part of the apparatus, and a rotary driving unit4 positioned in the lower part thereof. In the centrifugal tumbling unit3, a centrifugal tumbling chamber 6 for centrifugally tumbling thepowder grains 2 thrown thereinto and for performing a granulating andcoating processing. The centrifugal tumbling chamber 6 is composed of acylindrical fixed wall 7 served as a housing of the CF apparatus 1, anda rotating disk (or a rotating disc or a rotating dish) 5 centrifugallytumbling the powder grains 2 and served as a substantial bottom portionof the centrifugal tumbling chamber 6 for centrifugally tumbling thepowder grains 2. The upper part of the centrifugal tumbling chamber 6may be open, but portions other than portions required for communicatingwith the outside may be closed.

The fixed wall 7 has a powder contact portion 7 a which is in contactwith the powder grains 2 and which has a circular shape in a horizontalsection thereof, and a predetermined clearance 12 is formed between therotating disk 5 and an inner wall of the fixed wall 7. Herein, a reasonwhy the horizontal section of the powder contact portion 7 a is acircular shape is that movement of the respective powder grains to becentrifugally tumbled becomes smooth and a dead space is not formed.Therefore, the fixed wall 7 assumes the form of having a similarcircular horizontal section along the overall height of the centrifugaltumbling unit 3, but each sectional shape of portions other than thepowder contact portion 7 a is not limited to a circular shape. That is,the sectional shape of the fixed wall 7 may be a conical, spherical orquadrangular shape, and even if a part thereof is composed of the powdercontact portion 7 a having a circular section, the entire shape thereofis not limited to a cylindrical shape.

Materials for forming the fixed wall 7 are not restricted in particular,but various raw materials such as stainless steel, iron, light alloy,reinforced plastics or the like may be used as the above-mentionedmaterials. Lining formed of non-adhesive resin such as fluororesin,polyether or the like may be provided on a part or the entire of thepowder contact portion 7 a. Further, lining formed of non-adhesive resinmay also be provided on a central part 5 a or slope part 5 b of therotating disk 5 mentioned below. This lining prevents granulatedsubstances or coating processing substances from adhering to the powdercontact portion 7 a or the rotating disk 5.

An air supply device (an air supply means) 21 is provided above thecentral part of the rotating disk 5 in the centrifugal tumbling chamber6. FIG. 2 is an explanatory view showing a disposing state of the airsupply device 21, and shows a state seen from an upper portion of theair supply device 21 after a ceiling portion of the centrifugal tumblingchamber 6 is omitted. This air supply device 21 is composed of astraight tube portion 25 formed in a straight cylinder shape, and anumbrella-like air supply port 23 disposed in a lower side of thestraight tube portion 25. The straight tube portion 25 and the airsupply port 23 communicate with each other inside, and the straight tubeportion 25 is connected to a not shown air-sending means such as ablower or the like provided outside of the CF apparatus 1.

The air supply device 21 is fitted in such a state as to be capable ofmoving in the centrifugal tumbling chamber 6 in an up-and-down directionby a driving means not shown. Further, the air supply device can movebetween an upper position H indicated by a single dot chain line in FIG.1 and a lower position L indicated by a solid line. However, needles tosay, the air supply device 21 may be disposed to have a fixed structure.

The conical air supply port 23 of which the lower side is expanded in aradius direction is provided at a lower end of the straight tube portion25. This air supply port 23 is designed to cover the rotating disk 5with a lower end portion thereof like an umbrella when the air supplydevice 21 is lowered at the lower position L. From an opening portion 23a of this air supply port 23, dry air 22 can be widely supplied to anupper side of the rotating disk 5. The dry air 22 is ejected from a gapbetween a lower end peripheral edge 23 b of the air supply port 23 andthe rotating disk 5. As a result, the granulated substances arefluidized in the centrifugal stumbling chamber 6, and drying thereof ispromoted. That is, in the above-mentioned CF apparatus 1, it is possibleto dry the granulated substances generated by this dry air 22, and toperform from a granulation processing to a drying processing in a singleapparatus.

Further, a feed pipe 9 for feeding the powder grains 2 to the rotatingdisk 5 is provided from above the centrifugal tumbling chamber 6, with athrow-in port 9 a being opposite to the rotating disk 5. A spray nozzle15 is also provided to spray the powder grains 2 with the binding liquidor powders stored in a tank not shown. In this case, a nozzle having atwo-fluid or three-fluid structure may be used as the spray nozzle 15.The spray nozzle 15 may be disposed above a powder grain layer as shownin the drawing, or disposed so as to spray on the powder grain layerfrom a side direction thereof, or disposed at such any other positionsas to be capable of supplying the spray solution into the powder grains.

The rotating disk 5 is composed of a central part 5 a which is formed ina plane shape and positioned in a central side thereof, and a slope part5 b inclined straightly and downward toward the center thereof at theoutside of this central part 5 a. In the above-mentioned CF apparatus 1,a vertical section of the rotating disk 5 is defined to have such arelation that a dimension (P) of the rotating disk 5 in a horizontaldirection satisfies P≧0.25 D relative to the diameter (D) of therotating disk 5 (preferably 0.4D≧P≧0.25D). A height (H) from the centralpart 5 a to the slope portion 5 b is within a range of 0.1D≦H≦0.33Drelative to the diameter (D) (preferably 0.1D≦H≦0.25D). Hence, in theabove-mentioned CF apparatus 1, the centrifugal force created by therotating disk 5 is utilized effectively and sufficiently, and the powdergrains 2 are centrifugally tumbled effectively on the slope portion 5 b.

A conical projecting portion 8 is formed at the center of the centralpart 5 a of the rotating disk 5, and thereby distortion of the rotatingdisk 5 is prevented and strength thereof is ensured. Further, by thisprojecting portion 8, the powder grains 2 near the center of therotating disk 5 is aggressively moved to the slope portion 5 b on whicha centrifugally tumbling action is carried out.

Of an inner wall of the fixed wall 7, a portion with which the powdergrains 2 are in contact during the centrifugal tumble, that is, thepowder contact portion 7 a is substantially formed in a perpendicularstate relative to the central part 5 a of the rotating disk 5.Therefore, the powder grains 2 which are centrifugally tumbled on therotating disk 5 are upward pushed along the powder contact portion 7 a,without receiving any extra resistance.

In a lower side of the fixed wall 7, an air supply port 7 b is opened totake slit air 10 circulating through the clearance 12 between therotating disk 5 and the fixed wall 7, in a fluid chamber 11 formed inthe lower side of the rotating disk 5. Air taken therein is the slit air10 passing through the annular clearance 12 from the fluid chamber 11,and is introduced into the centrifugal tumbling chamber 6. In this case,the above-mentioned clearance 12 is formed with such a width that thepowder grains 2 in the centrifugal tumbling chamber 6 may not drop outfrom the clearance when the slit air 10 is supplied from beneath.Therefore, since the slit air 10 is circulated through the clearance 12,the powder grains 2 are prevented from falling from the clearance 12 andwhen the powder grains 2 are charged into the centrifugal tumblingchamber 6, these powder grains 2 are entirely supported by the rotatingdisk 5.

As shown in FIG. 3, flow amount of slit air 10 may be adjusted byforming a taper-like convex portion 31 inside the fixed wall 7, and byinstalling the rotating disk 5 capable of moving in an up-and-downdirection, and thereby varying width of the clearance 12.

On the other hand, in the rotary driving unit 4, a motor (a rotarydriving means) 13 that rotates the rotating disk 5 and is accommodatedin a casing 14 is provided. A shaft 13 a of this motor 13 is fixed on arotational center axis of the rotating disk 5, and thereby the rotatingdisk 5 may be rotated in a horizontal direction.

Next, operation of the present embodiment will be explained. Theabove-mentioned CF apparatus 1 performs a granulation processing, withthe air supply device 21 being lifted to the upper position H. After agranulating step, the CF apparatus makes the air supply device 21 pulleddown to the lower position L, and subsequently performs a dryingprocessing.

First, in the granulating step, with the air supply device 21 beingdisposed at the upper position H, air supply is stopped, andpredetermined amounts of powder grains 2 which are processing materialsto be processed on the rotating disk 5 in the centrifugal rotatingchamber 6 are thrown in from the throw-in port 9 a of the feed pipe 9.At this time, powder grains-used as materials may be powders, or may bepowders served as kernels. A granulating condition may be imposed suchthat a granulation or coating processing is performed during air supplyfrom the air supply device 21, with the air supply device 21 beingdisposed at the lower position L.

Further, while the slit air 10 from the clearance 12 is circulated, therotating disk 5 is rotated by the motor 13 and the powder grains 2 arecentrifugally tumbled on the rotating disk 5. In this case, the rotatingdisk 5 has any rotating speed, but usually a rotating speed of about 30to 300 rpm.

Moreover, in order to make powders adhering to each other or makepowders adhering to respective surfaces of kernel particles, the insideof the centrifugal tumbling chamber 6 is sprayed with a solutionobtained by dissolution of a solvent or binding liquid, a dispersionsolution such as emulsion or suspension, or a fused solution accordingto circumstances, from the spray nozzle 15. Only one of these solventand solution may be used in accordance with properties of the powdergrains or with granulated substances desired, or the other to which oneis changed may be used in accordance with processing steps ofgranulation. In the case of using the solution, substances having thesame elements as the powder grains are usually used, but othersubstances having elements different from elements that the powdergrains contain may be also used. Further, as occasion demands, powdersmay be fed during the granulating step.

Thus, the powder grains 2 are centrifugally tumbled on the rotating disk5 in the centrifugal tumbling chamber 6, and binding liquid or powdersis supplied to the powder grains 2 which have been centrifugally tumbledon the rotating disk. Accordingly, the powder grains 2 are centrifugallytumbled and thereby are spherically granulated.

Spherical particles subsequent to the spherical granulation describedabove, or separately manufactured spherical particles may be chargedinto the apparatus according to the present invention, and the particlesmay be coated with a medicine or an elution control layer. In additionto spherical particles, respective surfaces of amorphous particles orpowders may be also coated with a medicine or an elution control layer.

When granulated particles each reach a desired particle size, supply ofsolvent or solution is stopped and the granulation processing isterminated. At this time, since the above-mentioned apparatus 1 adoptsmuch the same granulation processing as the conventional single-functiontype CF apparatus, it is possible to granulate spherical particles ofwhich each particle size is small and which exist within a narrow rangeof the particle size distribution. Needless to say, large sphericalparticles can be also manufactured. Further, operating conditions may beimposed such that amorphous particles, or oblate particles having nospherical form such as an ellipse shape, a “go” stone shape or the likebut having a certain pseudo-spherical form, or a coagulation-likeparticles are manufactured in addition to spherical particles.

After this granulating step, the drying processing of granulatedsubstances is performed. In the conventional CF apparatus, because thedrying capacity of the apparatus is poor, the drying processing isperformed by transferring the granulated substances to other devices. Incontrast, the above-mentioned CF apparatus 1 can granulate thegranulated substances having the same properties of spherical form andthe same particle sizes as the conventional apparatus, and can furtherperform the drying processing inside the same apparatus.

That is, after the granulating step, air supply is started from the airsupply device 21 having lifted to the upper position H in advance, andthe air supply device is gradually moved to the lower position L. Dryair 22 from the air supply device 21 is introduced into a granulatedsubstance layer located on the rotating disk 5, and thereby a fluidstate is formed. As a result, the granulated substances are quicklydried by the dry air 22, and thereby products containing desiredspherical particles can be efficiently manufactured. At this time, byenlarging the above-mentioned clearance 12 and increasing flow amountsof slit air 10, enhancement of the drying capacity thereof can befurther achieved.

During the drying step, the rotating disk 5 may be in a rotating orstopped state. The height of the lower position L of the air supplydevice 21 is not particularly restricted, but it is preferable that atleast one part of the air supply device 21 enters into a laminatinglayer of the granulated substances, and that the granulated substancesare fluidized or moved in an up-and-down direction like a nearly fluidstate by the dry air 22. That is, even in the above-mentioned CFapparatus 1, it is desired to dispose the air supply device 21 at such aposition that an edge of the opening portion 23 a of the air supply port23 is buried in particle layers, and to thereby improve the dryingcapacity thereof.

As described above, the above-mentioned CF apparatus 1 according to thepresent invention can granulate heavy spherical particles of whichrespective particle sizes are small and which exist within a narrowrange of the particle size distribution, similarly to the conventionalsingle-function type CF apparatus, and further can perform the dryingprocessing inside the same apparatus. Therefore, it is possible tomanufacture products having properties obtained by using thesingle-function type CF apparatus, at productivity nearly equal to theproductivity capable of being achieved by the multifunction type powdergrain processing apparatus, and so to manufacture efficiently productswhich meet market needs.

In the above-mentioned apparatus, such various processing patterns areavailable as to perform “drying after granulation”, or “drying aftercoating”, or “both coating and drying (drying while coating) aftercoating”, or “granulation and then coating and thereafter drying”, or“both coating and drying after granulation”, or the like. In theabove-mentioned embodiment, the processing form of “drying aftergranulation”, among the various processing patterns, means that thegranulation processing is performed by disposing the air supply device21 at the upper position H and thereafter the drying processing isperformed at the lower position L. However, in this case, all theprocessings may be performed at the lower position L by performing boththe granulation processing and the drying processing, with the airsupply device 21 being disposed at the lower position L.

And, as mentioned above, in the above-mentioned apparatus, the coatingprocessing is also performed, and the processing form of “drying aftercoating”, among the various processing patterns, means that the coatingprocessing of particles generated after the granulation processing or ofparticles separately charged may be performed by disposing the airsupply device 21 at the upper position H, and thereafter the dryingprocessing may be performed at the lower position L. Further, after theair supply device 21 is disposed at the lower position L from the first,the coating processing and the drying processing may be performedcontinuously (“drying after coating”) or simultaneously (“both coatingand drying”).

Further, the above-mentioned apparatus can also perform a series ofprocessings composed of “granulating and then coating and thereafterdrying”. At this time, at least the drying step is performed bydisposing the air supply device 21 at the lower position L, but duringthe granulation processing and/or the coating processing, the air supplydevice 21 may be disposed either at the higher or lower position. Thatis, all processings from granulation to drying may be performed at thelower position L, or only the granulation processing may be performed atthe upper position H.

In addition, even when the processing of “both coating and drying aftergranulating” is performed, the processing step of performing dryingduring at least coating is performed by disposing the air supply device21 at the lower position L. However, during the granulation processing,the air supply device 21 may be disposed either at the higher or lowerposition.

On the other hand, the air supply device 21 is not limited to one shownin FIG. 1, and can adopt various forms thereof. FIGS. 4 to 10 show afirst to seventh modified examples of the air supply device 21 designedto supply the dry air 22 from above the central part of the rotatingdisk 5, respectively. Drawings following FIG. 4 show only a principalpart of the apparatus. Description of parts common to the parts shown inFIG. 1 will be omitted, and members and parts similar to the air supplydevice 21 shown in FIG. 1 are denoted by the same reference numbers anddetailed description thereof will be omitted.

The apparatus shown in FIG. 4 has the air supply device 21 that isformed only by the straight tube portion 25 and is disposed in a centerarea of the centrifugal tumbling chamber 6 and has no umbrella-like airsupply port 23. In this case, the opening portion 25 a of the straighttube portion 25 is formed above the projecting portion 8. Further, therotating disk 5 is also formed in such a plate shape as to raise an edge5 c from an outer periphery portion thereof.

The apparatus shown in FIG. 5 uses a rotating disk, 5 having such ashape that the center part 5 a of the rotating disk 5 shown in FIG. 1 iseliminated and the slope portion 5 b is formed toward a base portion ofthe projecting portion 8 from the edge thereof. Further, the openingangle of the air supply port 23 of the air supply device 21 is also setto be larger than that of the air supply port shown in FIG. 1.

The apparatus shown in FIG. 6 uses the air supply device 23 formed by ataper-like cylindrical member of which an upper end portion is enlargedin a radius direction thereof.

In the apparatus shown in FIG. 7, the fixed wall 7 of which foot isnarrowed is used. The slope portion 5 b of the rotating disk 5 is formedto have the same slanting angle as a foot narrowing portion 7 c of thefixed wall. In this case, the air supply device 21 is used in which sucha flange 24 as to cover nearly an upper surface of the rotating disk 5is provided on the air supply port 23.

In the apparatus shown in FIG. 8, the fixed wall 7 is formed in a curvedshape. In this case, a horizontal section of the powder contact portion7 a of the fixed wall 7 is formed in a circle shape as a section ofsphere. The air supply device 21 is used which is the same as the deviceshown in FIG. 5. The rotating disk 5 is used which has the projectingportion formed in such a shape as to thin and sharpen the projectingportion 8 of the rotating disk 5 shown in FIG. 1, such that when the airsupply device 21 is lowered to the lower position L, a tip of theprojecting portion 8 arrives at a position of the opening portion 25 aof the straight tube portion 25.

The apparatus shown in FIG. 9 has the rotating disk 5 of which theprojection portion 8 is formed in a hemispheric shape and of which theslope portion 5 b is curvedly raised from the base portion of theprojecting portion 8 and thereafter is straightly formed. The air supplydevice 21 is used which has such a shape that a side wall 23 c of theair supply port 23 is raised along the slope portion 5 b of the rotatingdisk 5, contrary to the air supply device having been described so far.In this case, a cover 26 is provided between an upper edge of the sidewall 23 c and the straight tube portion 25 such that the granulatedsubstances scattered are prevented from-staying the inside of the sidewall 23 c.

The apparatus shown in FIG. 10 is used which has the rotating disk 5 ofwhich the projecting portion 8 is formed in an elliptical andhemispherical shape and of which the slope portion 5 b is also formedlike a curved surface. In this time, the air supply device 21 is usedwhich has a flange 23 d formed at the lower end peripheral edge 23 b ofthe air supply port 23 shown in FIG. 1.

Second Embodiment

Next, as a second embodiment of the present invention, explanation willbe made of a CF apparatus having a form of supplying the dry air 22 fromabove the peripheral part of the rotating disk 5 by means of the airsupply device 21. FIG. 11A and FIG. 11B are explanatory views showingprincipal parts of a CF apparatus that is the second embodiment of thepresent invention, wherein FIG. 11A is a cross-sectional view and FIG.11B is a perspective view seen from above.

In the apparatus shown in FIG. 11A and FIG. 11B, the air supply device21 adopts a thick cylinder-like straight tube portion 25. A clearance 27is formed between the straight tube portion 25 and an inner surface ofthe fixed wall 7, and the dry air 22 circulates through this clearance27. As shown in FIG. 11A, an opening portion 27 a of the clearance 27 isformed at the lower end of the straight tube portion 25. The dry air 22is supplied toward the slope portion 5 b positioned at the peripherypart of the rotating disk 5, from above through this opening portion 27a. As a result, the dry air 22 is supplied to the granulated substanceslocated on the rotating disk 5, and the drying processing of thegranulated substances is performed. Even in this present embodiment, theair supply device 21 is disposed so as to be movable in an up-and-downdirection.

On the other hand, even in the case of supply of the dry air 22 fromabove the peripheral part of the rotating disk 5, various modifiedexamples may be assumed. FIG. 12 and FIG. 13 show a first and secondmodified examples of the CF apparatus of the second embodiment,respectively.

In the apparatus shown in FIG. 12, the straight tube portion 25 of theair supply device 21 disposed in the center of the centrifugal tumblingchamber 6 is branched at the upper portion of the rotating disk 5, andeach branch pipe 28 has a form of extending above the periphery of therotating disk 5 and of having an opening. In this case, the number ofbranch pipes 28 shown in FIG. 12 is two, but the number thereof may beproperly increased or decreased, for example, a part of the straighttube portion to be branched may be equally divided into four pipes.

In the apparatus shown in FIG. 13A and FIG. 13B, a plurality of straighttube portions 25 of the air supply device 21 are arranged at theperiphery part of the centrifugal tumbling chamber 6. In the apparatusshown in FIGS. 13A and 13B, as shown in FIG. 13B, four straight tubeportions 25 are equally divided and provided, and the dry air 22 issupplied to the peripheral part of the rotating disk 5 from therespective opening portions disposed at lower ends thereof. In this casetoo, the number of straight tube portions 25 may be properly increasedor decreased, for example, two, six or the like.

Third Embodiment

Further, as a third embodiment of the present invention, explanationwill be made of the CF apparatus having a form of supplying the dry air22 to the rotating disk 5 from a side direction of the centrifugaltumbling chamber 6. FIG. 14 is an explanatory view showing a principalpart of the CF apparatus that is a third embodiment of the presentinvention.

In the apparatus shown in FIG. 14, the air supply device 21 is arrangedat the fixed wall 7. The air supply device 21 is opened at an upper sideportion of the rotating disk 5, and the dry air 22 is supplied upwardthe rotating disk 5 from the opened portions. In this case,opening-and-closing doors 30 are provided in opening portions 29 of theair supply device 21, and these opening-and-closing doors 30 are closedduring the granulating step. In the drying step, the doors are opened,and thereby the dry air 22 is introduced into the centrifugal tumblingchamber 6.

Fourth Embodiment

Next, as a fourth embodiment, explanation will be made of the apparatusthat adds a dewing prevention means to the centrifugal tumbling device.FIG. 15 is an explanatory view showing a principal part of a CFapparatus that is a fourth embodiment of the present invention. FIG. 16is an explanatory view showing a fragment of a part thereof. FIG. 17 isan explanatory view showing a disposing state of the air supply device21, and shows a view of the air supply device 21 seen from above after aceiling portion of a centrifugal tumbling chamber 6 is omitted.

Herein, like the apparatus shown in FIG. 1, in the apparatus of whichthe centrifugal tumbling chamber 6 is separated from the outside aironly by the fixed wall 7 made of metal, the fixed wall is directlycooled by the outside air. Due to this, portions locally having atemperature of the dew point or less are generated on the inner surfaceof the fixed wall 7, and so moisture in the centrifugal tumbling chamber6 is dewed in such portions. For example, in the case of an atmospherein which the inside of the centrifugal tumbling chamber 6 has atemperature of 70° C. and a humidity of 60%, if the temperature islowered to 58° C., the humidity is increased to 100%. Therefore,portions that have been cooled by the outside air and of which thetemperature arrives at 58° C. or less C come to a dew point zone, anddewing is generated in this zone.

If dewing is generated, then splash of binder or powders may adhere toand be solved in the moisture thereof, and thereby the solved substancesfunction as adhesive, and the powder grains adhere to the solvedsubstances. And, the powder grains act as kernels, and further otherpowder grains adhere to the powder grains, and the other powder grainsadhering to the powder grains spread over the entire area of the fixedwall. This not only requires time and labor for cleaning the apparatusbut also affects product yield and operation efficiency of theapparatus, so that improvement thereof is being desired.

Thereupon, in the apparatus that is the fourth embodiment, as shown inFIG. 15 and FIG. 16, the centrifugal tumbling chamber 6 has a doublewall structure, and a vacuum adiabatic chamber 33 is formed at theoutside of the fixed wall 7, and thereby this structure prevents thefixed wall 7 from being affected by the external temperature. That is,since the fixed wall 7 is provided with the adiabatic chamber 33 as adewing prevention means, the inside of the fixed wall 7 does not lowerto a temperature of the dew point or less.

In the above-mentioned CF apparatus, first, an outer wall 32 is providedto surround the entire of the fixed wall 7. An adiabatic chamber(adiabatic space) 33 is airtightly formed between the fixed wall 7 andan outer wall 32. Also between the fixed wall 7 and the outer wall 32,stainless steel spacers 34 each having a diameter of about 1 to 2 mm arearranged so as to be in contact with both walls.

The outer wall 32 is further provided with an exhaust port 35 forexhausting air of the inside of the adiabatic chamber 33. The exhaustport 35 is connected to a vacuum pump (pump device) 36 provided outsideof the apparatus. By operating the vacuum pump 36 and thereby suckingair of the inside of the adiabatic chamber 33, the inside of theadiabatic chamber 33 results in such a state as to be filled with gashaving lower pressure than the atmospheric pressure. That is, the insideof the adiabatic chamber 33 comes to a vacuum state. At this time, thespace inside the adiabatic chamber 33 is ensured even by the spacers 34arranged between the fixed wall 7 and the outer wall 32.

The inside of the adiabatic chamber 33 is a medium vacuum state (10² to10⁻¹ Pa) or a high vacuum state (10⁻¹ to 10⁻⁵ Pa). However, byconsidering a rigidity of the apparatus and an adiabatic effect, thepresent embodiment adopts a vacuum of 13.3 Pa (0.1 Torr) or less,preferably 13.3 to 1.33 Pa (0.1 to 0.01 Torr) from relation between costand effect thereof.

Thus, if the adiabatic chamber 33 is set to be in a vacuum state,conducting heat is cut off at both inside and outside of the apparatus.That is, even if there is temperature difference between the inside ofthe centrifugal tumbling chamber 6 and the outside of the apparatus, thefixed wall 7 is not cooled directly by the outside air temperature. Dueto this, even if the inside of the centrifugal tumbling chamber 6 comesto high temperature and high humidity, then the fixed wall 7 is cooledby the outside air and thereby dewing cannot be generated on the innersurface thereof. Therefore, the powder grains do not adhere to the innersurface of the fixed wall 7, and cleaning jobs are alleviated, andimprovement of production efficiency or the like can be achieved.

In the above-mentioned embodiment, the adiabatic chamber 33 is set to bein a vacuum state and dewing of the fixed wall 7 is prevented, but thetemperature of the fixed wall 7 may be prevented from lowering bysupplying warm water, heated oil or the like into the adiabatic chamber33. Or, the fixed wall 7 may be heated electrically or inductively initself, without adopting the double wall structure.

Moreover, as the apparatus shown in FIG. 18 and FIG. 19, the dry air 22may be supplied from above the peripheral part of the rotating disk 5 inorder to correspond to the apparatuses shown in FIG. 12 and FIG. 13.

Fifth Embodiment

Further, as a fifth embodiment, explanation will be made of an apparatusadding a slip prevention means to the rotating disk 5. FIG. 20 is anexplanatory view showing a constitution of a rotating disk that is afifth embodiment of the present invention and which is seen from above.FIG. 21 is a perspective view thereof. FIGS. 22A and 22B and FIG. 23 areeach a explanatory view showing a constitution of a slip preventiongroove. A constitution except for the rotating disk 5 is the same as theconstitution of the CF apparatus shown in FIG. 1 or FIG. 15.

In the apparatus shown in FIG. 1 and FIG. 15, the surface of therotating disk 5 is formed in a smooth surface, that is, in such a statethat surface roughness thereof is smaller, in order to perform thespherical granulation effectively. However, as described above, if theentire surface of the rotating disk 5 is smooth, then the powder grainsare easy to slip on the surface thereof and so, in turn, impede tumblingmotion.

Thereupon, in the fifth embodiment, as shown in FIG. 20 and FIG. 21,slip prevention grooves (slip prevention means) 37 are provided on therotating disk 5, and thereby strengthening gripping force is achieved.That is, in the above-mentioned apparatus, the slip prevention grooves37 are radially and spirally formed on the entire surface of the powdercontact portion of the rotating disk 5, and the powder grains are ledtherein and thereby the tumbling action is promoted. Each slipprevention groove 37 is formed as a strip-like groove of about 0.5 to 2mm, on the smoothly formed surface of the rotating disk 5. The sectionalshape of each slip prevention groove 37 is set as corresponding torotating directions of the rotating disk 5, and a side wall 37 a locatedin a front side of the rotating directions is formed to have a moderateslope, and a side wall 37 b located in a rear side thereof is formed tohave a steep slope. That is, in the case where the rotating disk 5 shownin FIG. 20 rotates in a left-hand direction, each groove is formed asshown in FIG. 22A and FIG. 23A, and in the case of a right-handrotation, each groove is formed as shown in FIG. 22B and FIG. 23B.

Thus, since the slip prevention grooves 37 are formed on the rotatingdisk 5, the powder grains disposed on the rotating disk 5 arespherically granulated on the smooth surface portion thereof and, at thesame time, tumbling of the powder grains is promoted by the slipprevention grooves 37. That is, slipping of the powder grains isprevented and the centrifugal gripping force is strengthened, so thattumbling of the powder grains is activated. It is therefore possible tocentrifugally tumble and granulate, or powder-coat the powder grainscertainly, and achieve high speed rotation of rotating disk, tightgranules, improvement in processing capacity of small quantity, and thelike.

On the other hand, in the fifth embodiment, the rotating disk 5 is shownin which concave grooves are formed as the slip prevention means butalternatively the slip prevention means may be formed in a ridge-likeconvex portion. Moreover, strip-like grooves may be provided not in theentire surface of the powder contact portion of the rotating disk 5 buta part thereof, for example, the peripheral part thereof. Further, eachslip prevention groove 37 is not limited to a curved form as shown inFIG. 20, and may be a form that is extended radially and linearly.

As a slip prevention means, whole or a part of the surface of therotating disk 5 may be formed in a pear-skin shape or a baffle may bedisposed on the rotating disk 5.

Sixth Embodiment

Additionally, in a sixth embodiment, explanation will be made of theapparatus in which a swirl flow generating means is added to the airsupply device 21. FIG. 24 is an explanatory view showing a constitutionof the CF apparatus that is a sixth embodiment of the present invention.FIG. 25 is an explanatory view showing an air blast state flowing fromthe air supply device.

In the apparatus shown in FIG. 1 or FIG. 15, an air blast from the airsupply device 21 is supplied onto the rotating disk 5 in a verticaldirection, and is presented for granulation or drying. However, sincethe air blast is linear as mentioned above, the air blast is easy topass through over the rotating disk 5 and the circulating time on therotating disk tends to be shorter.

Thereupon, in the sixth embodiment, as shown in FIG. 24 and FIG. 25, theair supply device 21 is provided with agitators (wind introducingplates) 38 to generate a swirl air stream, and enhancement of theprocessing efficiency is achieved. That is, in the above-mentionedapparatus, a plurality of agitators 38 is provided in the air supplyport 23 of the air supply device 21, and thereby a swirl wind issupplied onto the rotating disk 5. Each agitator 38 is a crescent-likesteel plate having a thickness of about 5 to 10 mm, and is radiallyarranged on the inner wall of the air supply port 23. Between theadjacent agitators 38, a wind introducing path 39 is formed radially andspirally.

These wind introducing paths 39 are formed from the upper portion of theair supply port 23 toward the opening portion 23 a. The air streampassing through these paths becomes a swirl air stream as shown in FIG.25, and is supplied onto the rotating disk 5. As a result, swirl motioncan be given to the respective powder grains on the rotating disk 5, andthe powder grains are wound up in a spiral-rotation shape so as to twista rope. Therefore, it is possible to promote tumbling of the powdergrains and to achieve improvement of the processing efficiency. It isalso possible to prevent the air stream from blowing through straightlyas indicated by broken lines in FIG. 25, and thereby to lengthen contacttime between the air stream and the respective powder grains. Therefore,since stay time when the air stream stays in the powder grain layerlengthens, the drying efficiency thereof can be enhanced.

It is preferable that, in the apparatus shown in FIGS. 1, 2, 3, 5, 8 and10, agitators are installed on the inner wall of the air supply port 23in the air supply device 21, and, in the apparatus shown in FIGS. 4, 7,9, or 11, agitators are installed on the inner wall located in a lowerend side of the straight tube portion 25. Further, in the apparatusshown in FIG. 6, agitators are installed on the inner wall located inthe lower end side of the taper expanded portion.

On the other hand, in the apparatus shown in FIGS. 12, 13, 18 or 19, aswirl air stream can be obtained by disposing obliquely the branch pipe28 or the straight tube portion 25 toward a rotating direction thereofand by supplying the air onto the rotating disk 5 along the rotatingdirection. However, agitators may be provided on the wall located in thelower end portion of the branch pipe 28 or the straight tube portion 25.Further, in the apparatus shown in FIG. 14, a swirl air stream can beobtained by mounting obliquely the air blast tube of the air supplydevice 21 on the fixed wall 7. In this case, it is more effective thatthe air supply device 21 is disposed in a tangential direction of thefixed wall 7 and the dry air 22 is supplied in a tangential direction ofthe rotating disk 5.

Each shape of the agitators 37 is not limited to a crescent shape, andas far as the wind introducing paths 39 each having a radial and spiralshape can be formed, a square shape formed by twisting a strip-shapeplate member may be also used, for example.

As described above, the inventions made by the present inventors havebeen concretely explained on the basis of the embodiments. However, thepresent inventions are not limited to these embodiments, and needless tosay may be changed and modified without departing from the gist thereof.

For example, it is also possible to provide at least one baffle or guideplate for adjusting the tumbling action, inside the fixed wall 7.Moreover, sensors for detecting temperature, humidity, contentsaccumulating amounts, or the like may be provided in the centrifugaltumbling chamber 6 in order to control each step performed by the CFapparatus 1. Further, filters such as bag filters, cartridge filters orthe like, or cyclone, or the like may be provided therein, or a devicefor performing heating, cooling, dehumidifying or the like of the dryair 22 or the slit air 10 may be provided. In addition, it is possibleto provide a temperature adjusting means of jacket or the like outsideof the fixed wall 7.

The above-mentioned embodiments and modified examples are mere examplesof the present invention, and also the combination of the air supplydevice 21 and the rotating disk 5 is not limited to the above-mentionedexamples. Needless to say, the first to sixth embodiments may beproperly combined, for example, by using the air supply device 21 shownin FIG. 1 in the rotating disk 5 shown in FIG. 4.

INDUSTRIAL APPLICABILITY

According to the centrifugal tumbling granulating apparatus and thepowder grain processing method that are the present invention, the airsupply device for supplying dry air is provided above the rotating disk,and the granulated substances are dried by this dry air. Therefore,since the granulated substances can be dried inside the same apparatus,it is unnecessary to perform the drying processing by transferring thegranulated substances to other drying devices and thereby improvement ofproductivity thereof can be achieved. In this case, the productsgranulated come to heavy spherical particles that can not be obtained bythe conventional multifunction type granulating coating apparatus, andof which each particle size is small, and which exist within a narrowrange of the particle size distribution. Accordingly, it is possible toproduct efficiently spherical particles with high quality.

Also according to the centrifugal tumbling granulating apparatus of thepresent invention, since the fixed wall is surrounded by an outer walland an adiabatic space is formed between the fixed wall and the outerwall, heat conduction is cut off by this adiabatic space and it ispossible to suppress heat conduction of the air to the fixed wall.Therefore, the fixed wall is cooled by the air, and thereby it ispossible to prevent dewing from being generated on the surface thereofand to suppress adhesion of the powder grains to the inner surface ofthe fixed wall. As a result, the cleaning jobs are alleviated, theproduct yield and the apparatus operation efficiency are improved, andimprovement of the production efficiency or the like can be achieved.

Further, by providing the powder contact portion of the rotating diskwith a slip prevention means, the powder grains are prevented fromslipping on the rotating disk, and the centrifugal gripping force isstrengthened, and the tumbling of the powder grains is activated.Therefore, the powder grains can be centrifugally tumbled and granulatedcertainly, and high speed rotation of the rotating disk, tight granules,improvement of processing capacity of small quantity, and the like canbe achieved.

In addition, by providing the air supply means with the a swirl flowgenerating means for supplying swirl wind onto the rotating disk, it ispossible to give swirl motion to the powder grains located on therotating disk, and to promote the tumbling of the powder grains, and toachieve improvement of the processing efficiency. The air stream is alsoprevented from blowing through straightly, and the contact time betweenthe air stream and the respective powder grains can be lengthened, andthe stay time of the air stream staying in the powder grain layers canbe lengthened, and thereby the drying efficiency can be enhanced.

What is claimed is:
 1. A centrifugal tumbling granulating apparatuscomprising: a fixed wall having a grain contact portion which is incontact with powder grains and of which a horizontal section is formedat least in a circular shape; a rotating disk provided a predeterminedclearance away from an inner side of said fixed wall and rotating in ahorizontal direction by a rotary driving mean; and an air supply meansdisposed above said rotating disk and close to said rotating disk andsupplying gas to an upper surface side of said rotating disk, whereinsaid air supply means is provided to be movable in an up-and-downdirection between a lower position close to said rotating disk and anupper position more remote from said rotating disk than said lowerposition.
 2. The centrifugal tumbling granulating apparatus according toclaim 1, wherein said air supply means supplies gas to said rotatingdisk from above the central part of said rotating disk.
 3. Thecentrifugal tumbling granulating apparatus according to claim 2, whereinsaid air supply means has a cylindrical straight tube portion, and anair supply port which communicates with said straight tube portion andis disposed below said straight tube portion and of which a lower endside is enlarged in a radius direction of said portion and is formedlike a cone.
 4. The centrifugal tumbling granulating apparatus accordingto claim 1, wherein said air supply means supplies gas to said rotatingdisk from above a peripheral part of said rotating disk.
 5. Thecentrifugal tumbling granulating apparatus according to claim 1, whereinsaid air supply means is disposed in such a state that a part thereofenters in to a particle layer of said powder grains.
 6. The centrifugaltumbling granulating apparatus according to claim 1, wherein saidrotating disk has such a vertical section that a peripheral part thereoffaces a center thereof and is inclined downward.
 7. The centrifugaltumbling granulating apparatus according to claim 1, wherein saidrotating disk has a projecting portion in a central part thereof.
 8. Thecentrifugal tumbling granulating apparatus according to claim 1, whereingas is supplied to said clearance formed between said fixed wall andsaid rotating disk, from a lower direction thereof to an upperdirection.
 9. The centrifugal tumbling granulating apparatus accordingto claim 1, wherein said fixed wall has a dewing prevention means forpreventing an inner surface of said fixed wall from being dewed.
 10. Thecentrifugal tumbling granulating apparatus according to claim 9, whereinsaid dewing prevention means comprises an outer wall surrounding saidfixed wall, and an adiabatic space formed between said fixed wall andsaid outer wall.
 11. The centrifugal tumbling granulating apparatusaccording to claim 10, wherein said dewing prevention means furthercomprises a pump device for sucking air from the inside of saidadiabatic space.
 12. The centrifugal tumbling granulating apparatusaccording to claim 10, wherein said adiabatic space is filled with gashaving lower pressure than atmospheric pressure.
 13. The centrifugaltumbling granulating apparatus according to claim 12, wherein the gas insaid adiabatic space has a pressure of 1.33 Pa or less.
 14. Thecentrifugal tumbling granulating apparatus according to claim 1, whereinthe powder contact portion of said rotating disk is formed to have asmooth surface.
 15. The centrifugal tumbling granulating apparatusaccording to claim 1, wherein a slip prevention means for preventing thepowder grains on said powder contact portion from slipping is providedin the powder contact portion of said rotating disk.
 16. The centrifugaltumbling granulating apparatus according to claim 15, wherein said slipprevention means is a strip-like groove radially formed in the powdercontact portion of said rotating disk.
 17. The centrifugal tumblinggranulating apparatus according to claim 16, wherein said strip-likegroove is formed such that a side wall of a front side along a rotatingdirection of said rotating disk is smoother than that of a rear sidealong said rotating direction.
 18. The centrifugal tumbling granulatingapparatus according to claim 1, wherein said air supply means isprovided with a swirl flow generating means for supplying swirl windonto said rotating disk.
 19. The centrifugal tumbling granulatingapparatus according to claim 18, wherein said swirl flow generatingmeans is a wind introducing plate arranged in said air supply means. 20.The centrifugal tumbling granulating apparatus according to claim 1,wherein said air supply means is disposed in such a state as to inclinetoward a rotating direction of said rotating disk from above saidrotating disk, and supplies gas onto said rotating disk along therotating direction to thereby form a swirl air stream.
 21. A powdergrain processing method comprising the steps of: charging the powdergrains into a rotating disk of a centrifugal tumbling and granulatingapparatus, the apparatus comprising: a fixed wall having a grain contactportion which is in contact with the powder grains and of which ahorizontal section is formed at least in a circular shape; the rotatingdisk provided a predetermined clearance away from an inner side of saidfixed wall and rotating in a horizontal direction by a rotary drivingmeans; and an air supply means disposed above said rotating disk andprovided to be movable in a up-and-down direction between a lowerposition close to said rotating disk and an upper portion more remotefrom said rotating disk than said lower position; rotating said rotatingdisk while gas is supplied to an upper direction of said clearance froma lower direction thereof; supplying at least one of solvent, solution,dispersion solution, and dissolved solution, and then performing one ofgranulation and coating of said powder grains; and drying granulatedsubstances of said powder grains by supplying gas to an upper surfaceside of said rotating disk from said air supply means.
 22. The powdergrain processing method according to claim 21, wherein a swirl airstream is supplied from said air supply means.
 23. The powder grainprocessing method according to claim 21, wherein powders are furthersupplied into said centrifugal tumbling and granulating apparatus. 24.The powder grain processing method according to claim 21, wherein saiddrying step is performed with said air supply means being disposed atsaid low position.
 25. The powder grain processing method according toclaim 24, wherein at least one of the granulating step and coating stepis performed, with said air supply means being disposed at said upperposition.
 26. The powder grain processing method according to claim 21,wherein at least one of the granulating step and the coating step isperformed, with said air supply means being disposed at said lowerposition close to said rotating disk.
 27. The powder grain processingmethod according to claim 21, wherein supply of gas from said air supplymeans is stopped in one of said granulating step and coating step. 28.The powder grain processing method according to claim 21, wherein gas issupplied from said air supply means in one of said granulating step andcoating step.